De-doming an XM-L [New XM-L2 with handmade Ti reflector, pic heavy]

Hey everybody, I’ve got a question. I have a small copper light that is direct drive with an XM-L U2 (MBI HF). It’s in the gas as we speak. The thing is, it’s mounted on an Al star and fujik’d in the copper head, with a pcb below the emitter holding a spring.

Will the gasoline soften or cause the Fujik to release? I figured that if it does, I’ll pull the emitter/star out of there when it’s done de-doming and remove the emitter from that star, relocate it to a copper star to give it better heat sink to the copper head.

The MBI HF is hitting 500+ lumens as a direct drive light on an IMR style 10250 specially made cell. It can’t run long, but it’s brilliantly bright on a fresh cell! Being in a 2” light, there’s not a lot of reflector (and it’s only about a half inch in diameter) so it’s been very floody. I’m hoping this dedome tightens that up considerably and helps get rid of the greenish tint that was on the U2.

Would love to hear what y’alls experience says about this.

Will post some pics later as it comes out of the gas all fresh and clean. :slight_smile:

I just dedomed a Skyray Kung’s emitters. Let pill and emitters sit around 8 or more hours. Doms came off but emitter bases were still stuck to pill. It does look like some of the fujik-type stuff dissolved, but I have not tried to pry off the bases yet.

The dome came off at 4 hours, but I pulled it off. Don’t know if I broke these 2 wires then or when picking the left-over pieces off with tweezers.

So I used liquid solder to join the wires back to their base by moving them back into position (viewed at 1:1 Macro and 10X magnification through Live View on my camera)

Then I got to looking at it and am confused. Will this liquid solder short it out? Why does it appear that the single 4th wire to the side joins the negative and positive plates together? So will this work or should I even bother putting power to it?

Anybody know?

The wire off to the side is ESD protection, ignore it (or rip it off).

You should be good to go if everything's making good contact. The upper plane of the substrate as shown in your pics is the positive (base of the die is where it makes the + connection), lower plane that the bond wires jump to is the negative.

Music to my ears. Now how do I get rid of the gasoline smell on the copper? lol I rinsed it in denatured alcohol, but the gasoline smell is still strong on the metal itself. Pick it up for even a few seconds and your fingers smell like a chemical plant.

So rinse more. Alcohol won't hurt it like acetone will.

Those are amazing pictures. Hope the liquid solder works for you. Please report back.

Great info Comfy.

What kind of gasoline are you using that gets the dome off in 4-8 hours?

Just regular octane gas for lawn mower, a couple of months old. In 4 hours the dome lifted right off, but of course that’s probably how I tore those 2 wires…didn’t wait for it to float off.

I’ve got it back together, working fine with a tighter warmer beam and it looks kick aus inside that little light! The emitter is closest to the glass you’ll get in a light most likely, so the wires are plainly visible, looks really cool, works really cool (er, warm) as well.

Pics uploading. Will be back directly.

11 consecutive shots in landscape mode, stacked in Photoshop CS5. 1:1 Macro. Illuminated with the Texas Poker, on med. at about 11 inches.

On low, ~40 lumens, 1/8000 sec F/13 ISO 100

Your closeups are always amazing. Also, that HF makes a dedomed XM-L look huge.

Looks great!!

This emitter is in an MBI HF Copper light, I also have an MBI HF Titanium light with an XM-L T5 Neutral White emitter. So I compared these as the beam profile would remain the same due to both being XM-L emitters. After these tests, run on matching Efest IMR10440 cells, they were both pulling ~2.42A (each had spikes but they settled in around that two and a half mark)


HF Cu XM-L U2 De-domed

Ceiling shots at a white Styrofoam ceiling tile 1 foot square from ~8 feet. (the room has 9 foot ceilings, lay on the floor with the camera on my chest, light held beside the camera in the other hand)


HF Cu XM-L U2 De-domed

It would be interesting to see the results from a sphere as to what the lumens output is on a light before and after de-doming. To my eyes, this light has a green tint to it’s emitter, had it before and it’s still there. But the camera seems to prefer it to the Neutral White T5, showing that one as a warmer tint.

The HF XM-L T5

The HF XM-L U2 De-domed

At ~60 yds distance: T5

U2 Dedomed

This one an XM-L2 T6 for a Ti HF. And I did some other modding as well. When I de-domed the XM-L2 I tried to file down the backside of the reflector to bring the emitter further up into it since it now sits real low. Also, the copper star is thicker than the thin aluminum one that was under the XM-L T5 so the bezel wouldn’t screw on with the o-ring installed. Messed up and went too far, got a big dark spot in the middle of the beam. :frowning: So I figured I’d make it a mule. Which meant it needed a spacer ring to hold the lens. Made that from a .45 Long Colt brass which worked well, but put a gold ring around the outer beam. And me being a Ti fanatic, didn’t like the brass in my Ti light.

Here’s what the brass did to the beam

Here’s the Ti HF, on top, with it’s siblings and cousin all from MBI

So I set out to make a new reflector this morning. From surgical Ti, grade 23 6AL4V. :slight_smile: Yep, did it with a cordless drill and a Sears rotary tool (cheap dremel)

Here’s a comparison to the aluminum reflector that came out of it.

And a ceiling beamshot on the 1 square foot white Styrofoam ceiling tiles.

A control shot in the darkened living room

And with the new emitter and reflector

Very pleased with these modifications! The beam is now a nice warmish neutral white, nice large hot spot with an even balance of spill. Runs longer before heat becomes an issue with the copper star and I’m really liking how the Ti reflector turned out. I spent a bit more time polishing the internal this evening and it’s as much like a mirror finish as I can get Ti to have. This Ti has a neat greyish color, so no it’s not as shiny (bright) as chrome would be. But it works fine and I’m loving the beam so it’s all good! :slight_smile:

Thanks for checking it out. :slight_smile:

Thanks for sharing!

Nice mods DBC. You must have eyes on you like an eagle.

Wow! You are the first I am aware of to successfully repair LED bond wires. Great job!

Your Ti reflector is simply amazing!

I wonder if the bond wires are stronger or weaker now? Also noticed they’re completely different on the XM-L2. Don’t know if a repair like this would work on that one. Glad I didn’t have to try!

I just spent the afternoon putting one of Erik’s drivers in a Solarforce M3 head, swapped out the aluminum star for copper but kept the XM-L U2. So I now have a much harder driven Solarforce M3 L2P…3.45A on Hi! :slight_smile: Seriously thought about de-doming it for the throw, but like it’s tint so I didn’t .

I’m quite pleased with the little Ti reflector myself! I think it aids in color tint for a very pleasing effect. And also adds just that much more Ti to a Ti light. :bigsmile:

I was remiss on my work with the M3 head. Forgot to let y’all know that I went back and de-domed the XM-L that I had swapped over to copper, and added 2 chips to Eriks driver.

So it now makes 4.2A and hits the barn at 610 yds! A small P60 style light that throws 600+ yds, it’s pretty impressive! Still has a bit of a blue tint but not as bad as before the de-dome. Not bad in and of itself but compared to the de-domed XM-L2 T6 in my HD2010 it’s still quite cool.

Good thing Erik’s drivers are 5 modes, that really comes in handy when you’re running over 4A!